Dangers of Sugar

Sugar is Killing Us. Here's Everything You Need to Know.

Sugar-related illnesses are skyrocketing (diabetes, heart disease, and dementia, among them). Yet Americans are shoveling in more sweet stuff than ever. We know it's bad. We just can't stop. Science shows it's not simply a matter of self-control: Sugar, it turns out, might be as addictive as hard drugs. Could you be hooked?

Sugar is Killing Us. Here's Everything You Need to Know.Sugar-related illnesses are skyrocketing (diabetes, heart disease, and dementia, among them). Yet Americans are shoveling in more sweet stuff than ever. We know it's bad. We just can't stop. Science shows it's not simply a matter of self-control: Sugar, it turns out, might be as addictive as hard drugs. Could you be hooked?

Jamie Chung

You'd never willingly eat poison, right? Okay, maybe you snack on not-so-healthy treats every so often. Or scarf down non-nutritious junk at happy hour. But straight-up poison? Never.

Or so you think.

"Sugar can act like poison in high doses—and the amount in our diets has gone beyond toxic," says Robert Lustig, M.D., a neuroendocrinologist at the University of California at San Francisco School of Medicine. The typical American now swallows the equivalent of 22 sugar cubes every 24 hours. That means the average woman eats 70 pounds—nearly half her weight—of straight sugar every year.

Both the American Heart Association and the World Health Organization recently released guidelines urging most women to stay under six teaspoons (i.e., six sugar cubes) of added sugar per day. "Sugar consumption is now an epidemic," says Mark Hyman, M.D., author of The Blood Sugar Solution 10-Day Detox Diet. "The long-term effects will be staggering."

And, no, we're not just talking cavities. When eaten in such vast quantities, sugar can wreak havoc on the body. Over time, that havoc can lead to diabetes and obesity, and also Alzheimer's disease and breast, endometrial, and colon cancers. One new study found that normal-weight people who loaded up on sugar doubled their risk of dying from heart disease. Other research pinpoints excess sugar as a major cause of nonalcoholic fatty liver disease, which can lead to liver failure.

No doubt about it, says Hyman: We're sweetening ourselves sick, yet screaming for more. Why? Because we're seriously hooked. Research shows that hyper-sweet foods may be as addictive as the hardest-to-quit drugs.

SUGAR RUSH
Our earliest ancestors likely downed about 20 teaspoons of sugar...per year, says Hyman. The body made its own glucose—an ingredient in sugar and the "energy of life" that powers your every cell—by breaking down healthy fats, proteins, and complex carbs, says Lustig. When people came across something sweet, their brains rejoiced, since sweet meant nutritious berries or fruits, says Ashley Gearhardt, Ph.D., a psychologist at the University of Michigan.

Problem is, research suggests that your brain still gets psyched by sweets—like, totally psyched. Bingeing on them in the modern form of added sugar can cause a surge of dopamine, the feel-good neurotransmitter, in your brain's reward center. Repeated spikes can desensitize that center, which could release less and less dopamine, leaving you needing more and more sugar to score a rush, says Nicole Avena, Ph.D., author of Why Diets Fail: Because You're Addicted to Sugar. "These are the same brain patterns you see during drug addiction."

Indeed, a recent study suggests that sugary cookies could be as addictive as cocaine or morphine. When scientists scanned the brains of subjects who'd just eaten a high-sugar treat, everyone's nucleus accumbens—the part of the brain that switches on when a person shoots heroin or smokes crack—was lit up like fireworks. By contrast, the control group that swallowed low-sugar fare had no nucleus accumbens activity.

That's not all: Avena's research shows that, for some, sugar dependence could come with withdrawal symptoms like those of a street drug addiction. "We see brain changes that lead to lethargy, anxiety, and irritability," she says. "And also changes that produce fierce cravings." Not helping matters are your taste buds, which suffer from their own sort of addiction: New research suggests that the more you weigh—and the more sugar you eat, the more you're likely to weigh—the duller your "sweet" taste buds can become, meaning you may have to shovel in even more sugar to get the same sensory satisfaction.

In other words, millions are now strung out on a substance as dangerous as it is ubiquitous, says Hyman. "What saved us as hunters and gatherers—that survival mechanism that rewarded us when we sought sweets—is now killing us."

HOW YOU GET SEDUCED
Just how vulnerable you are to sugar's sweet allure depends on an unquantifiable mash-up of dosage and genetics. "Sugar addiction is like gambling addiction," explains Anne Alexander, editorial director of Prevention and author of The Sugar Smart Diet. "Some people can walk into a casino, play the slots, and walk away. Others start mortgaging their house."

Most people fall somewhere in between, says Hyman. To see where you might lie on the sugar addiction spectrum, try sticking to six or fewer teaspoons of added sugar per day for one week. If you experience strong cravings or those drug-addiction-like withdrawal symptoms—or other ones such as poor concentration, headaches, or sadness—it's likely you're hooked on sweets. If you feel all right, your brain is probably not misfiring, though that's no excuse to up your sugar intake. Remember: Addictive or not, too much added sugar remains a health hazard.

SECRET STASH
"Most people are sugar overeaters but don't know it," says Nicole Avena, Ph.D. That's because some "healthy" foods are loaded with hidden added sugar. The FDA has proposed nutrition label changes requiring manufacturers to list natural and added sugars separately. Until then, we have only the "total sugar grams" line to go by. To stay under the recommended limit for added sugar (6 teaspoons or 24 grams per day), study labels—and be aware of what may be lurking in these foods.

PICK YOUR POISON
Ultimately, added sugar is added sugar—it all affects you roughly the same way, regardless of where it comes from. Below, where common forms fall on the spectrum of evil-doing.

High-Fructose Corn Syrup (HFCS)
Derived from corn starch, syrupy HFCS might be the scariest sweet. Much of it contains mercury, a by-product of chemical processing. But another danger is its high artificial fructose content, not to mention that it can be 75 times sweeter than white sugar. (Listen up, agave eaters: The processed nectar can be up to 85 percent fructose and possibly more damaging to your liver than HFCS!)

Maple Syrup and Honey
Often touted as far healthier than refined sugar, these do contain fewer chemicals and a better glucose-fructose balance (plus a few helpful antioxidants). However, says Anne Alexander, author of The Sugar Smart Diet, even if the unique flavors of maple syrup and raw honey may lead people to use less, these sweeteners can still spike the body.

Natural Sugar
Sweet news! Unless it's all you eat, it's hard to go overboard on truly natural sugars that come directly from fruits and some veggies. Here's the trick: You have to actually eat the produce. Fruit juices, even those without added sweeteners, will still sugar-bomb your bloodstream. The key is in the fiber, which slows sugar's absorption in your body, preventing an insulin spike. Any fruit is fair game. "Ones with the most natural sugar have the most fiber," says Robert Lustig, M.D.